Find the Latest State Air Pollution Emission Inventories

Air emissions inventories are detailed lists of air pollution released by large sources of emissions within a geographic area. The U.S. Environmental Protection Agency compiles state inventories into a national emissions inventory that is made available to the public every three years. However, by the time the national inventory is made available, data collected are nearly three years out of date and more recent information is available from state inventories. Annual state emission inventories are available to the public, but they are often difficult to find, and some states charge a fee to access the information.

As a public service, to help provide timely and convenient public access to this state information, the Environmental Integrity Project is making all these state inventories available on our website. The map below provides access to the most recent state emission inventories and a description of the data presented. Please click on a state to access its state emissions inventory website and data.

Federal regulations require states and sometimes counties or cities to collect air emissions data from large municipal, commercial, or industrial facilities like power plants, refineries, chemical plants, landfills and trash incinerators to compile the information into an inventory each year. These inventories are used to evaluate compliance with the Clean Air Act, to aid our understanding of air pollution in certain areas, to help develop air pollution laws, and in planning activities, like deciding where to place air quality monitors.

All state emissions inventories include common air pollutants that impact human health, known as criteria air pollutants and precursors, which include particulate matter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOCs), carbon monoxide (CO), and lead. Current federal regulations allow states to decide if facilities should be required report toxic or hazardous air pollutants (HAPs), a group of 188 pollutants that are most dangerous to public health or the environment, like benzene. As of 2023, 39 states require at least some facilities to report their toxic air emissions. Federal regulations also allow states to decide if smaller sources of air pollution should be required to report their emissions, or to have polluters report greenhouse gas emissions.

The EPA also compiles the Toxics Release Inventory (TRI) each year, which includes toxic air pollution emissions data from facilities that are required to report. However, many large sources of air pollution are not required to report to the TRI, and the TRI is limited to specific toxic chemicals.

Available emissions information varies by each state. In some cases, states may not maintain a state emissions inventory beyond what is provided to the EPA. In these cases, we provide copies of the data available from EPA.